The present invention relates to an A.C. generator to be driven by an engine of a vehicle such as an automobile and, particularly, to an improvement of a cooling system of such an A.C. generator.
A typical example of a conventional vehicle mounted A.C. generator is shown in Japanese kokai No. 83557/1984, which is shown, in cross section, in FIG. 1 of this application, which corresponds to FIG. 4 of the kokai. In FIG. 1, a rotary shaft 1 of the generator is driven by an engine of a vehicle through a pulley 2. A rotor 3 of the generator is mounted on shaft 1, and includes a pair of magnetic cores 4 between which an exciting coil is supported. Stator cores 5 are arranged in facing relation to the cores 4 with small gaps therebetween. Each stator core 5 supports a stator coil 6 in its slot.
The stator cores 5 are supported by a bracket 7 in which a circular coolant passage 8 is formed coaxially with the stator cores 5. A coolant inlet 9 and a coolant outlet 10 are formed in a front portion of the bracket 7 with an angle of 180.degree. therebetween to guide a coolant from the inlet 9 through the coolant passage 8 to the outlet 10. In the coolant passage 8, a plurality of heat radiating fins 11 are formed.
FIGS. 2 and 3 show a mounting of the A.C. generator to the vehicle engine. In these figures, reference numerals 12, 13, 14 and 15 depict the vehicle engine for driving the generator through the pulley 2, a cylinder block of the engine, a water jacket provided around the cylinder block 13 and a radiator for cooling the coolant heated in the water jacket 14, respectively. The radiator 15 is connected to the water jacket 14 through an upper hose 16 and a lower hose 17. The coolant which is pressurized in the lower hose 17 by a water pump 18 is supplied to the water jacket 14 and flows therethrough and through the upper hose 16 to the radiator 15. A portion of the pressurized coolant flows through a tube 19 connected to the coolant inlet 9 into the coolant passage 8 in the bracket 7 and is returned through the outlet 10 and a tube 20 to the lower hose 17. Since the coolant is pressurized by the water pump 18, it can circulate through the passage to cool heat generating portions such as stator coil 6, etc., effectively.
In the vehicle mounted A.C. generator mentioned above which is arranged in the front side of an engine compartment in which sufficient space is not available, the coolant inlet 9 and outlet 10 are arranged in the bracket 7 with an angle of 180.degree. therebetween. Therefore, the inlet 9, the outlet 10 and the tubes 19 and 20 which occupy a relatively large space generally may constitute obstacles against other components to be arranged in the engine compartment.